Do Not Tap on the Glass.

Situation
Situation puzzles (sometimes called lateral thinking puzzles) are ones where you need to ask lots of yes or no questions to figure out what happened in the situation. These are good puzzles for groups where one person knows the puzzle and answers the questions.

A man works at an aquarium. Every day he spends a large chunk of his time trying to stop people from tapping on the glass at the shark tank. Finally, fed up with it, he comes up with a solution. The solution works perfectly; the next day no one taps on the glass. However, he is fired for it. What was the man's solution?

Hint

The plan took some effort to do and not everyone could accomplish it.

Answer

The man painted a crack on the glass. Fearing it would break, no one touched it. However, since it made the aquarium seem unsafe and it scared the patrons, he was fired.